NASA Troubleshooting Artemis II Rocket Upper Stage Issue

NASA is troubleshooting an interrupted flow of helium to the upper stage of the Space Launch System rocket for the Artemis II mission. The issue was observed overnight Feb. 21 at Kennedy Space Center in Florida. Teams are preparing to potentially roll back the rocket and Orion spacecraft to the Vehicle Assembly Building to address the problem. The upper stage uses helium to maintain proper environmental conditions for the engine and to pressurize liquid hydrogen and liquid oxygen tanks. The systems operated during wet dress rehearsals that ended Feb. 19, but helium could not be properly flowed during normal operations and reconfigurations afterward. Operators are using a backup method to maintain conditions while the rocket stays in a safe configuration. Engineers are reviewing data and examining potential causes in the interface between ground and rocket lines, a valve in the upper stage, and a filter between the ground and rocket. They are also consulting data from the Artemis I mission, which required similar helium pressurization troubleshooting. Preparations include removing pad access platforms installed the previous day because of wind constraints and forecasts for high winds. A rollback would mean missing the March launch window. The steps could preserve the option for an April window depending on data findings and repair efforts. NASA will continue to provide updates.